mpeg warning

[rogerdpack]

I notice this warning when transcoding an mpeg stream:

[mpeg2video @ 0xb730b840] warning: first frame is no keyframe

for instance this file
http://rogerdpack.t28.net/incoming/sintel.mpg

this command line:
:sout=#transcode{vcodec=h264,vb=300,scale=0.25,acodec=mp4a,ab=128,channels=2,samplerate=22050}:rtp{mux=ts,sdp=rtsp://:8554/test.sdp} :sout-keep

Or if I just play it:

[mpeg2video @ 0x9ab3e00] ac-tex damaged at 40 7
[mpeg2video @ 0x9ab3e00] Warning MVs not available
[mpeg2video @ 0x9ab3e00] concealing 1035 DC, 1035 AC, 1035 MV errors
[mpeg2video @ 0x9ab3e00] ac-tex damaged at 40 7
[mpeg2video @ 0x9ab3e00] Warning MVs not available
[mpeg2video @ 0x9ab3e00] concealing 1035 DC, 1035 AC, 1035 MV errors


This file came "direct" from the DVD. Anyone know what these might mean?
Thanks.
-r

[Lotesdelere]

[mpeg2video @ 0xb730b840] warning: first frame is no keyframe
[mpeg2video @ 0x9ab3e00] ac-tex damaged at 40 7
[mpeg2video @ 0x9ab3e00] Warning MVs not available
[mpeg2video @ 0x9ab3e00] concealing 1035 DC, 1035 AC, 1035 MV errors
[mpeg2video @ 0x9ab3e00] ac-tex damaged at 40 7
[mpeg2video @ 0x9ab3e00] Warning MVs not available
[mpeg2video @ 0x9ab3e00] concealing 1035 DC, 1035 AC, 1035 MV errors

I'm getting the same warnings from FFmpeg, I can demux the file but I can't remux it, looks like it has been badly muxed in the first place.